Omeprazole therapy does not affect pharmacokinetics of orally administered ethanol in healthy male subjects

The purpose of this study was to study the effect of high-dose omeprazole therapy (20 mg twice daily) on kinetics of moderate amounts of orally administered ethanol. Eight healthy men participated in the study. After an overnight fast, they drank 0.5 g/kg body weight ethanol over 20 min. Blood samples were drawn before and then every 20 min after ethanol ingestion for the next 3 h. Subjects then ingested omeprazole 20 mg twice daily for 6 days. On the seventh day, the same dose of oral ethanol was administered as before and blood samples drawn. Blood ethanol concentrations were determined. We fit a one-compartment model with first-order absorption and zero order elimination to the blood ethanol data with PCNONLIN (SCI Software, Lexington, KY, U.S.A.) separately for each subject before as well as after omeprazole therapy. Area under the curve was calculated using the trapezoidal rule. There were no differences in the peak concentration, time to peak concentration, area under the curve, or elimination rate constant for ethanol before and after omeprazole treatment. Omeprazole treatment (20 mg twice daily) does not affect the pharmacokinetics of orally ingested ethanol in healthy male subjects. Our results do not rule out a possible effect on psychomotor function as a result of a pharmacodynamic interaction.